rt, soe we : . o : wee tomate ob ee eek at poe Le ye Pe ne . woe . pT Tete oO And, at the same time, the difference in | 60 a fa Ae TAR ee TEE SeesSater . the Sitayer AE ‘47. Co content between ‘the goatfish from near the crater and those at Bikini I. is by a factor of about ten. ‘ 207_. ; It appears that the physical redistribution of Bi is similar to that of £000, but since the levels of 207... Bi are lower than those of 6006 by a factor of about 20, we are at the for samples distant limits of detection, with the method used, from the crater. The use of larger samples, chemical separation and more sensitive counting methods would make it possible to . determine 60 Co: 207... . . . Bi ratios in sediments, lagoon water and organisms in different parts of the lagoon. These ratios would indicate whether transported radionuclides were primarily in solution or on particles. If the ratios remained constant, that would be a strong indication of transport on particles. results of analyses of selected samples for The 207_., . Bi by gamma-ray spectrometry and by chemical separation are compared in Table 13. Bismuth-207 will be a useful tracer in the future because it has a long half-life, 30 years compared to 5.2 years for °° ergy Cepartment of En Histcrians Office ARCHIVES ~ Plutonium-239, with a half-life in excess of 24,000 years, is another potentially useful tracer. d The samplesanalyze plutonium were selected on the bases of collection location and content of gamma-emitting radionuclidess, which indicate 9001341 for